PARIS — Companies in the United States, Spain, Canada and Finland lead the world in employing the largest numbers of women from entry level to senior management, according to a report published Monday by the World Economic Forum. Yet the report also found that, despite increasing awareness of gender disparities in the workplace, women at many of the world’s top companies continued to lag behind their male peers in many areas, including pay and opportunities for professional advancement.

Moreover, many of these companies have yet to implement policies to address these gaps, despite pressure from many of their governments to do so.

The forum, based in Switzerland, surveyed 600 heads of human resources offices at the largest employers in 20 countries representing 16 different industries.

The poll assessed companies according to a range of criteria, including rates of female representation, whether the companies measured or set targets for gender balance in pay or promotion, and whether they offered benefits, like paid family leave, to promote work-life balance for their employees.

The findings, which were timed to coincide with the 100th anniversary of International Women’s Day, follow the announcement Friday by the European Union of an initiative aimed at significantly narrowing the union’s average 18 percent gender wage gap, which has changed little in the past 15 years.

A study by the 27-member union last year estimated that closing the wage gap could lead to a potential increase of 15 percent to 45 percent in gross domestic product.

A 2009 report by the International Labor Organization found an average 20 percent difference in pay for men and women employed full time in the Group of 20 largest developed and developing economies. Yet the World Economic Forum’s report found that 72 percent of the companies in its survey had no systems to track salary differences by gender.

In addition, 60 percent of the companies said they had no affirmative action policies to promote women within their hierarchies and did not measure women’s participation in their work forces.

Companies in India had the lowest percentage of female employees, 23 percent, just below Japan, with 24 percent, the forum’s report found.

Turkey, Austria and Italy rounded out the bottom five, with women representing just 26 percent, 29 percent and 30 percent of their staffs, respectively.

As its focus was on companies, the forum’s survey did not assess the status of women working in the public sector or in education, areas where female representation is traditionally high and where policies to promote gender balance are often institutionalized by law.

Women remained in the minority of senior corporate managers, representing just 5 percent of the chief executives of the 600 companies surveyed. Finnish companies in the sample had the largest proportion of female chief executives, with 13 percent, followed closely by Norway and Turkey with 12 percent and Italy and Brazil with 11 percent.

The high percentage of female chief executives at Turkish companies, despite having relatively low levels of female employment, was due to the fact that many of the biggest companies were controlled by families where women were at the helm, said Saadia Zahidi, co-author of the report and head of the forum’s Women Leaders and Gender Parity Program. In Italy, which reported similarly large numbers of women at the top, the companies surveyed were mainly large, multinational corporations.

In both countries, Ms. Zahidi said, “there is a real dearth of women elsewhere in the corporate hierarchy.”

The forum’s findings also follow a global study of 4,500 business school graduates published last month by Catalyst, a U.S.-based organization that advocates for women in the workplace.

The Catalyst study found that, even in this high-potential group, women consistently lagged behind men in advancement and compensation from their very first professional job. The differences held even in comparing men and women of equal levels of work experience and professional aspiration and in discounting for whether or not they had children.

Herminia Ibarra, a professor of leadership and organizational behavior at Insead, an international business school, and a co-author of the forum’s report, said of the findings, “Study after study shows that, in most countries and industries, women enter the workplace pipeline in representative numbers. Then, something fails to happen.”